library(plm)
## Loading required package: Formula
library(lmtest)
## Loading required package: zoo
## 
## Attaching package: 'zoo'
## 
## The following objects are masked from 'package:base':
## 
##     as.Date, as.Date.numeric
data<-plm.data(data)
summary(data)
##        公司       individual       year            Q         
##  *ST二重 :  9   777    :  9   Min.   :2005   Min.   :0.5533  
##  丹甫股份:  9   922    :  9   1st Qu.:2007   1st Qu.:1.1765  
##  东方电气:  9   967    :  9   Median :2009   Median :1.5447  
##  东方锆业:  9   2130   :  9   Mean   :2009   Mean   :1.8858  
##  哈空调  :  9   2167   :  9   3rd Qu.:2011   3rd Qu.:2.1786  
##  海陆重工:  9   2255   :  9   Max.   :2013   Max.   :6.5207  
##  (Other) :126   (Other):126                  NA's   :69      
##       roe                roa             存货周转率        总资产周转率   
##  Min.   :-1.76565   Min.   :-0.14813   Min.   :  0.4627   Min.   :0.1140  
##  1st Qu.: 0.04355   1st Qu.: 0.03151   1st Qu.:  1.4496   1st Qu.:0.3357  
##  Median : 0.07607   Median : 0.05106   Median :  2.3721   Median :0.4879  
##  Mean   : 0.04032   Mean   : 0.04676   Mean   :  8.2026   Mean   :0.5388  
##  3rd Qu.: 0.12360   3rd Qu.: 0.07572   3rd Qu.:  3.6278   3rd Qu.:0.6724  
##  Max.   : 0.66163   Max.   : 0.35168   Max.   :328.7956   Max.   :1.4773  
##  NA's   :69         NA's   :69         NA's   :68         NA's   :69      
##    资产负债率     营业收入增长率     流动资产周转率   营业收入增长率.1  
##  Min.   :0.1457   Min.   :-0.56564   Min.   :0.1731   Min.   :-0.56564  
##  1st Qu.:0.3371   1st Qu.: 0.00604   1st Qu.:0.5127   1st Qu.: 0.00604  
##  Median :0.4713   Median : 0.11323   Median :0.6986   Median : 0.11323  
##  Mean   :0.4995   Mean   : 0.45272   Mean   :0.8044   Mean   : 0.45272  
##  3rd Qu.:0.6560   3rd Qu.: 0.24394   3rd Qu.:0.9323   3rd Qu.: 0.24394  
##  Max.   :0.9569   Max.   :23.31517   Max.   :2.1825   Max.   :23.31517  
##  NA's   :69       NA's   :83         NA's   :68       NA's   :83        
##  应收账款周转率   
##  Min.   : 0.3386  
##  1st Qu.: 1.5867  
##  Median : 2.7812  
##  Mean   : 3.7116  
##  3rd Qu.: 3.8664  
##  Max.   :32.4027  
##  NA's   :68
pdim(data,index = c("individual","year"))
## Balanced Panel: n=20, T=9, N=180
pooling<-plm(roe~存货周转率+总资产周转率+资产负债率+营业收入增长率+流动资产周转率+应收账款周转率,data = data,model = "pooling",index = c("individual","year"))
summary(pooling)
## Oneway (individual) effect Pooling Model
## 
## Call:
## plm(formula = roe ~ 存货周转率 + 总资产周转率 + 资产负债率 + 
##     营业收入增长率 + 流动资产周转率 + 应收账款周转率, 
##     data = data, model = "pooling", index = c("individual", "year"))
## 
## Unbalanced Panel: n=17, T=3-9, N=97
## 
## Residuals :
##    Min. 1st Qu.  Median 3rd Qu.    Max. 
## -1.4700 -0.0568  0.0241  0.1160  0.7310 
## 
## Coefficients :
##                   Estimate  Std. Error t-value Pr(>|t|)   
## (Intercept)     0.16679289  0.10847635  1.5376 0.127656   
## 存货周转率      0.00046706  0.00084216  0.5546 0.580540   
## 总资产周转率    0.53024320  0.20017339  2.6489 0.009537 **
## 资产负债率     -0.52927806  0.15563273 -3.4008 0.001004 **
## 营业收入增长率  0.00740193  0.01228822  0.6024 0.548449   
## 流动资产周转率 -0.25908673  0.12798798 -2.0243 0.045903 * 
## 应收账款周转率  0.01245290  0.00720790  1.7277 0.087477 . 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Total Sum of Squares:    8.8951
## Residual Sum of Squares: 7.1179
## R-Squared      :  0.1998 
##       Adj. R-Squared :  0.18538 
## F-statistic: 3.74538 on 6 and 90 DF, p-value: 0.0022598
timemodel<-plm(roe~存货周转率+总资产周转率+资产负债率+营业收入增长率+流动资产周转率+应收账款周转率,data = data,model = "within",effect="time",index = c("individual","year"))
summary(timemodel)
## Oneway (time) effect Within Model
## 
## Call:
## plm(formula = roe ~ 存货周转率 + 总资产周转率 + 资产负债率 + 
##     营业收入增长率 + 流动资产周转率 + 应收账款周转率, 
##     data = data, effect = "time", model = "within", index = c("individual", 
##         "year"))
## 
## Unbalanced Panel: n=17, T=3-9, N=97
## 
## Residuals :
##    Min. 1st Qu.  Median 3rd Qu.    Max. 
## -1.3900 -0.0837  0.0436  0.1230  0.4580 
## 
## Coefficients :
##                   Estimate  Std. Error t-value  Pr(>|t|)    
## 存货周转率      0.00097431  0.00087342  1.1155 0.2678850    
## 总资产周转率    0.46217965  0.20493153  2.2553 0.0267796 *  
## 资产负债率     -0.62122139  0.15794875 -3.9331 0.0001746 ***
## 营业收入增长率  0.00609054  0.01239691  0.4913 0.6245304    
## 流动资产周转率 -0.26240580  0.12888607 -2.0360 0.0449836 *  
## 应收账款周转率  0.01418470  0.00743438  1.9080 0.0598929 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Total Sum of Squares:    8.2077
## Residual Sum of Squares: 6.3181
## R-Squared      :  0.23023 
##       Adj. R-Squared :  0.19463 
## F-statistic: 4.08753 on 6 and 82 DF, p-value: 0.0012292
fixef(timemodel)
##      2005      2006      2007      2008      2009      2010      2011 
## 0.2744246 0.3366164 0.5703209 0.2176621 0.2033117 0.3111619 0.1522088 
##      2012      2013 
## 0.2388265 0.1816575
timecoef<-fixef(timemodel)
timecoef<-as.numeric(timecoef)